Method of electric welding and brazing



(No Model.) 2 Sheets-Sheet l.

E. THOMSON. METHOD OF ELEGTRIO WELDING AND BRAZING.

' No. 403,708. Patented May 21 1889.

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E. THOMSON.

METHOD OF ELECTRIC WELDING AND BRAZING.

No. 403,708. Patented May 21 1889.

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UNITED STATES 4 PATENT OFFICE.

Elillll THOMSON, OF LYNN, MASSACIHTSE'FFS.

METHOD OF ELECTRIC WELDING AND BRAZlNG.

SPECIFICATION forming part of Letters Patent No. 403,708, dated May 21,1889.

Original application filed February 21, 1887, Serial No. 228,277

Divided and this application filed October 19, 1888. Serial No.

2 88,594. (No model.)

To all 71/71 07; it raw/y concern:

Be it known that l, ELIHL' TlHOMSON, a citizen of the United States, anda resident of Lynn, in the county of Essex and State of Massachusetts,have invented certain new and useful Improvements in ltlectric \Veldingand Brazingnil": which the following is a specification.

My invention relates to methods or processes of forming welded or brazedjoints between two metal pieces or portions of a metal object; and itconsists, essentially, in passing a heating electric current through thematerial from one side to the other of the joint, and then, when thematerial. is properly heated, subjecting the joint itself to compressionby suitable tools forced upon. the joint in. a lat eral or transversedirectionthat is to say,in a direction transverse to the general commonline or plane in which the joint and the object or portions of objectadjacent to the joint and on either side thereof lie.

The tools or means used for effecting compression or applying thepressure maybe dies, clamps, rollers, or other instrumentalitiessnitably forced against the hot metal to consolidate and perfect theweld or brazing.

The heating electric current may be any source proper for delivering acurrent of the requisite volume such, for instance, as that described inmy prior patent, No. 35AM).

My invention is applicable to the formation of either lap or buttjoints.

The invention consists, further, in giving to the material at eitherside of a butt-joint an enlargement by upsetting or otherwise preparatory to the operation of heating and applying the transversepressure.

My invention consists, further, in the special improved details of theprocess, as will be herein further described, and then more particularlyspecified in the claims.

In the accompanying drawings, forming part of this specification, Figure1 is a front elevation of an apparatus suitable for practicing myinvention. Fig. 2 is a side view of shows a joint fornicll by the deviceof Fig. l. Figs. and (i show the manner of forming the ends or abuttingport ions of bars or plates preparatory to the making of a weldedbutt-joint in accordance with my invention. Fig. 7 shows another form ofapparatus suitable for use in practicing my invention. Fig. 8 shows thejoint as formed between the plates, Fig. (3. Fig. 0 shows another formof apparatus similar to Fig. 7. Fig. 10 illustrates a specialapplication of my invention and the devices to be used therein.

In Fig.1, 0 U are clamps or holders, of any desired character, mountedon a plate or base, M, and insulated from one another. The clampsconnect by heavy cables or other devices with a source of very heavyelectric current, as described in my prior patents before referred to.The clamps serve to hold the bars or pieces to be welded and to conveycurrent thereto. In the present case the bars l3 l) in the clamps areshown as arranged to be united by a lap-welded joint where their endsmatch.

The clamps C U are good condi'ictors and are kept clean, making suchgood contact with the piece or pieces B B that current passes so as toheat that part of B B between the clamps to the welding or brazing heat.A pressure-clamp or die-press, G, is arranged to be used to presslaterally upon the bars atthe lap-joint and to force the two intimatelyinto contact. Brass and borax may also be applied where the joint iswanted to braze the pieces while pressed and held by the clamps.

The view Fig. 2 shows how the clamp C may be constructed to permit easyinsertion and removal of pieces operated upon.

S is a screw, which bears on an extension of the clamp-pillar P andforces the clamp (1 down hard upon the piece 13, pivots at p be ingprovided.

The clamp G may be made, as shown in Fig. 3, in the ordinary way or inany other way to give the pressure. It may carry tlat orcnrved die-facesF F, if it be desired to modify the shape at that part of the metal l3l3 operated upon. The die-surfaces F F should be faced with carbon,soapstone, or other non-cond uctor of heat of refractory nature.

The ends of bars formed as in Figs. l,

" 7 and 1'; may be placed together and united by "a perfect weld whenheated by the current.

In forming a butt-welded joint by the application of lateral pressure itis desirable that there should be an enlargement of the blank at theabutting edges, in order that on the application of the lateral pressurematerial may be present in sufficient quantity to form a good unionbetween the pieces without reducing the thickness at the finished joint.This enlargement may be given to the pieces o object in any desiredmanner, but is conveniently formed by upset-ting the materialpreparatory to the welding operation.

In cases where an extended seam or joint is to be formed the stationarypressure-clamp G may be replaced by rollers, as K K, Fig. 7, connectedto opposite sides of the circuit, so as to form electrodes between whichthe current passes through the metal to be operated upon. Thus in thecase of fiat plates, as in Fig. 6, to be welded edge to edge to form alongitudinal seam or joint, it is well to roll the joint bypressure-rolls during its formation, and in this case the rollers maybemade massive and of good conductor of electricity, not too easilymelted, and may be used to press the sheet or plate and convey currentthereto for heating the joint for welding, successive portions of theseam or joint, as the strips or plates, passing through the rollers.

In Fig. 7 the plates B B, whose edges where the joint is to be made havebeen previously upset, are firmly pressed together edgewise and therollers K K caused to press on each side oppositely while the platesprogress through the rollers slowly. A very heavy current passing at thesame time from roller to roller through the upset j ointing-edge softensthe metal and causes welding. A flux, as borax, is sometimes applied tothe joint. The eitect or result, as shown in Fig. 8, is a single plate.

In Fig. 9 the rolls K K are arranged to be adjusted as to proximity byscrews 8 s, as usual in rolling-mills, and are kept insulated at I I,but driven by gearing D, so as to move together. Guiding rolls H H H,insulated from K and K, are suitably placed according to the work to beguided or fed. Very heavy cables connect rolls K K to the source ofcurrent G.

It will be understood that the current need not be passed from roll toroll, as it would be clearly within my invention to pass the current, asin Fig. 1, between clamping-supports or otherwise, so that the part tobe operated upon by the rolls is heated by the electric current duringthe manipulation. Thus when a tube is to be welded, either by the lap orbutt weld, current may be caused to traverse it, as

in Fig. 1, to heat the portion to be operated upon, and an externalroll, K, Fig. 10, applied to shape the exterior and assist the union,while an internal mandrel, M, prevents collapse.

The roll K may be caused to traverse around the circumference of thetube T; or the tube T may be revolved and K pressed'against its side,while the heat is maintained by the current.

My present application forms a division of a prior application forpatent filed by me February 21, 1887, Serial No. 228,277.

I do not herein claim the improved process of forming a j unctionbetweensections of pipe or tubing, consisting in passing a current ofelectricity across the joint to heat the same to the welding temperatureand completing the welding operation over a mandrel introduced into thepipe or other article beneath the joint, as this process forms thesubject of another application for patent filed by me May 1, 1889.

NVhat I claim as my invention is A 1. The herein-described method offorming a welded or brazed joint, consisting in passing an electriccurrent through the material from one side to the other of the joint andthen applying lateral pressure directly to the material at the partwhere the joint or weld is to be formed.

2. The herein-described process of forming a butt-welded joint,consisting in forming or providing the met-a1 with an enlargement at thepoint of abutment, passing a heating electric current through thematerial, and then applying lateral pressure to the material directly atthe joint, as and for the purpose described.

3. The herein-described improved method of forming an elongated metaljoint, consisting in passing a heating electric current across the jointand applying transverse or lateral pressure to successive portions ofthe object directly at the joint, and for the purpose described.

4. The herein-described process of electric welding, consisting inpassing an electric current of large heating effect across the joint andthen compressing or compacting the joint by pressure applied laterallyin a direction transverse to the general line or plane, including thejoint and the pieces or portions of object adjacent to the joint.

Signed at Lynn, in the county of Essex and State of Massachusetts, this15th day of Octo-

